When making her professional debut, manga creator Hiromi Arakawa decided to work under the masculine-sounding pen name Hiromu Arakawa. The choice was probably made under the logic that a male author would be more easily accepted by the predicted male fanbase of the action-adventure stories Arakawa was crafting.
In the end, though, all of that worrying was probably unnecessary. Male readers have no issue with Arakawa’s gender because she can produce awesome adventure stories, and her series have enjoyed broad crossover appeal with female manga readers as well. As a matter of fact, so many of Arakawa’s fans are women that there are now two pairs of pumps inspired by her most successful series, Fullmetal Alchemist.